Resonant reed adjusting means



May 25y 1965 R. H. volGT 3,185,901

RESONANT REED ADJUSTING MEANS Filed May 5l, 1962 25 {2f} zs/zsn 23A/2427 -1-/ MM 25 I A 525H f/ 29 @3fm/23A INVEN TOR.

United States Patent O 3,185,901 RESONANT REED ADJUSTING MEANS Robert H.Voigt, Milford, Mich., assignor to Aseco, Incorporated, a corporation ofMichigan Filed May 31, 1962, Ser. No. 198,822 6 Claims. (Cl. 317,-182)The present invention relates to resonant reed relays and moreparticularly to a means for selectively varying the natural resonantfrequency of the resonant reed member of such a relay.

In certain copending applications Ser. No. 169,463, filed Ian. 29, 1962and Ser. No. 179,058 filed Mar. 12, 1962, now Patent No. 3,148,365,issued September 8, 1964, certain signal receiving units are disclosedwhich employ resonant reed relays. Input signals for such devices havenot been absolutely settled, and it might be necessary to adjust theresonant reed to respond to a different signal frequency than thatinitially decided upon. Also, it has been found in manufacturing theseunits that it is diicult to mass produce reeds which when installed inthe device have the same resonant frequency. There are several reasonsfor this diiculty. First the Youngs modulus may vary from one heat toanother. Secondly it is diicult to fabricate .the reed within thenecessary close tolerances to produce precisely uniform results. Third,it is difficult to mount the reeds in a sensing device in such a way asto insure that the effective length of the reed from the clamped ormounted end to the free end will be the same in each unit.

Heretofore various means have been employed to vary the resonantfrequency of the reed and thus overcome the above described difculties.One method has been to install a small band around the reed, preferablyat the free end, and by moving this band toward or away from the clampedor mounted end the natural resonant frequency of the reed will bevaried. This method has proven faulty since the band can readily vibrateout of position. Further such a method is time consuming and thereforeexpensive insofar as production costs are concerned.

Another method has been to fabricate the reed slightly' longer than therequired length and then tile the excess portion away after the reed hasbeen installed. Such a method is also time consuming and thereforeunduly expensive.

It is an object of the present invention to reduce manufacturing costsfor devices utilizing resonant reed relays by providing a means ofquickly and easily adjusting the natural resonant frequency of the reedmember of such a relay.

Another object of the present invention is to provide an improved meansfor varying the resonant frequency of a resonant reed member byproviding clamping means which may readily be adjusted to vary theeffective length of the reed.

Still another object of the present invention is to increase the utilityof devices actuated by an input signal of a predetermined frequency byproviding an improved resonant reed relay in which the natural resonantfrequency may be adjusted to respond to different actuation signals.

Still further objects and advantages will readily occur to one skilledin the art to which the invention pertains upon reference to thefollowing drawings in which like characters refer to like partsthroughout the several views and in which FIG. 1 is a diagrammatic viewof an electrical device illustrating one use of the resonant reedembodying the present invention.

FIG. 2 is an elevational side view of a preferred embodiment of thepresent invention, and

FIG. 3 is an elevational top view of the structure shown in FIG. 2.

Now referring to the drawings for a more detailed description of thepersent invention, FIG. 1 illustrates diagrammatically a preferredreceiving unit 10 embodying the present invention as comprising an inputline plug 11 connected to a resonance circuit 12. The resonance circuit12 preferably includes a capacitor 13 and an inductor coil 14 which forma series tuned LC circuit. The ca- .pacitive reactance of the capacitor13 would be approximately the same as the inductive reactance of theinductor coil 14 at a predetermined signal frequency imposed on thesupply line through the plug 11 and thus the reactances cancel oneanother and the circuit is resonant at that frequency.

A resonance relay 15 is disposed Within the magnetic field of theinductor coil 14 and preferably comprises a switch 16 having one contact17 carried adjacent a resonance reed 1S with the other Contact 19carried on a leaf 20 pivotally mounted on a hair spring 21.

The receiving unit 10 operates in the manner disclosed in my heretoforementioned copending patent application Ser. No. 169,463. The actuationsignal passes through the inductor coil 14 causing the resonance reed 18to vibrate at its natural frequency, in turn causing the contact 17 toengage the contact 19. When so resonated, the motion of the Contact 19is oscillatory at the same frequency due to the hair spring 21, so thatthe switch 16 remains closed, the contacts 17 and 19 moving together.

Upon the non-interrupting contact of the contacts 17 and 19 anelectromagnet 126 is energized to cause an armature 127 and pin 128 tomove to permit a uid cell diaphragm 129 to slowly expand. Expansion ofthe diaphragm 129 causes contacts 132-133-134 to engage, Engagement ofthe contacts 133-134 closes a circuit through resistors 107-108 andelectromagnet 126 so that armature 127 is held in position. Engagementof the contacts 132-133' closes a circuit through the inductor coil 14to cause a clapper 139 to vibrate to sound an alarm. Engagements of thecontacts 132-133 also closes a circuit through a heater winding 140.Contact 134 is preferably a bi-metal heat responsive element so that asthe winding heats up and after a predetermined time period the Contact134 will Warp to the dotted line position illustrated in FIG. 1 tode-energize the coils 14 and 126 and to return the receiver 10 to thestandby condition.

Element 104 is a D.C. rectifier and element 109 is a lamp connectedacross plug 11 to indicate whether or not there is suiiicient linevoltage `to operate the receiver.

The receiver 10 illustrated in FIG. 1 is just one of the severalreceivers disclosed in my aforementioned copending application and itWill be apparent as the description proceeds that the present inventionis not intended to be limited to the particular receiver 10 illustratedbut will find many uses in various electrical devices employing resonantcircuits.

FIGS. 2 and 3 illustrate in detail the resonance relay 15 with portionsremoved for clarity. A support member 22 is secured to the unit 10 inany desired fashion and provides the means by which a pair of resilientclamp members 23 are carried. f Screws or bolts 23A are provided tosecure the clamps 23 to the support 22.

The clamp members 23 are preferably provided with a longitudinal flatportion 24 and a substantially S-shaped portion 25 extending therefrom.The resonance reed 18 is sandwiched between the at portions 24 andsecured by the screws 23A, and has a free end portion 25A extendingoutwardly away from the clamp members 23 into an air gap preferably leftbetween the poles 14A of the inductor coil 14. A magnet 26 is carried onthe end of the reed 18 opposite the free end 25A. The clamp members 23arsenaal have a curved portion 27 engaging the reed member 1S at a pointspaced from the portion of the reed 18 held by the flat portions 24 ofthe clamp members 23. A bolt 28 extends through the S-shaped portion 25of the clamp members 23 and in combination with the nut 29 provides themeans by which the curved portions 27 of the clamp members 23 may bemoved longitudinally along the reed member 18 to vary the naturalresonant frequency thereof. When the bolt 23 is tightened, the portions25 tend to Hatten out, moving the portions 27 toward the free end of thereed. Thus a maximum effective reed length X and a minimum effectivelength Y are provided between which is a sufficient variation forproducing a relatively wide range of natural frequencies.

It is apparent from the foregoing description that a resonant reed relayhas been described in which difficulties heretofore experienced inproviding a reed having the required natural resonant frequency arelargely overcome. After the reed member 18 has been installed, the boltor screw 28 may be tightened which causes the clamping members 23 toexpand outwardly in the direction of the arrows in FIG. 2. This causesthe effective length of reed member i8 to be shortened and would act toincrease the natural resonant frequency of the reed. The head portion ofscrew 28 could extend through the cover of the unit 10 and thus permitthe adjustment of the reed 18 with the cover in place. This permits theconstruction of a unit which can be easily adjusted to respond to a newactuation signal.

The polarizing magnet 26 is installed with the poles axially alignedwith the reed 18 and serves to magnetically polarize the free end of thereed f8. In operation, the positive and negative cycles of the inputsignal would develop a magnetic north and a magnetic south attractiveforce which would cause the reed to respond since it would be polarizedwith either a north or south polarity.

Although I have described the present invention in cornbination with aspecific receiving unit, it is apparent that it may be used in manyother electrical and electronic devices and other changes andmodifications may be made without departing from the spirit of theinvention or the scope of the appended claims.

I claim:

1. In a resonant relay (a) a support member (b) a resonant reed member(c) mounting means securing one end of said reed member to said supportmember,

(d) said mounting means comprising a pair of clamp members, each of saidclamp members comprising a first portion and a second portion engagingsaid reed member,

(e) said first portions of said clamp members engaging opposite sides ofsaid reed member and said second portions being longitudinally spacedfrom said first portions and engaging opposite sides of said reedmembers,

(f) means fixing said first portions with respect to said reed memberand means selectively operable to move said second portionslongitudinally with respect to said reed member and Said first portionswhereby to vary the natural frequency of said reed member.

2. In a resonant relay (a) a support member (b) a resonant reed member(c) mounting means securing one end of said reed member to said supportmember,

(d) said mounting means comprising a clamping means embracing said reedmember,

(e) said clamping means comprising an end portion engaging oppositesides of said reed member and means fixing said end portion with respectto said reed member,

(f) said clamping means further comprising a second portionlongitudinally spaced from said end portion iand engaging opposite sidesof said reed member, and means selectively operable to move said secondportion longitudinally with respect to said reed member whereby to varythe natural frequency of said reed member.

3. In a resonant relay (a) a support member (b) a resonant reed member(c) mounting means securing one end of said reed member to said supportmember,

(d) said mounting means comprising a pair of resilient clamp memberscarried on said support member,

(e) each of said clamp members comprising a straight portion, a medialcurved portion and an end portion,

(f) said straight portions being fixed to opposite sides of said reedmember, said curved portions being outwardly spaced from said reedmember and said end portions engaging opposite sides of said reedmembers, and

(g) means selectively operable to urge said curved portions one towardthe other and toward a flattened position whereby said end portions aredisplaced longitudinally with respect to said reed member to vary theresonance frequency thereof.

4. The relay as defined in claim 3 and in which said last mentionedmeans comprises a screw member passing through said curved portions andsaid reed member and threaded means receiving said screw member.

5. In a resonant relay (a) a support member (b) a resonant reed member(c) mounting means securing one end of said reed member to said supportmember,

(d) said mounting means comprising a pair of resilient clamp members andmeans securing said clamp members to said reed member and said supportmember,

(e) each of said clamp members comprising a straight portion, a medialcurved portion connected with said straight portion and an end portionlongitudinally spaced from said straight portion by said curved portion,

() said straight portions engaging opposite sides of said reed memberand said securing means comprising at least one screw member passingthrough said straight portions, said reed member and said support memberwhereby axial movement of said straight portions with respect to saidreed member is prevented,

(g) said curved portions being spaced from said reed member and said endportions engaging opposite sides of said reed member, and

(lz) means selectively operable to urge said curved portions one towardthe other whereby said end portions are moved axially away from saidstraight portions to vary the resonance frequency of said reed member.

6. The resonance relay as defined in claim 5 and in which said lastmentioned means comprises a screw member passing through said curvedportions and said reed member and threaded means receiving said screwmember.

References Cited by the Examiner UNITED STATES PATENTS 853,001 5/07Bryant 200-90 2,953,726 9/ 60 Wunderlich 317-147 FOREIGN PATENTS 681,7039/ 39 Germany.

JOHN F. BURNS, Primary Examiner.

WALTER L. CARLSON, Examiner.

1. IN A RESONANT RELAY (A) A SUPPORT MEMBER (B) A RESONANT REED MEMBER(C) MOUNTING MEANS SECURING ONE END OF SAID REED MEMBER TO SAID SUPPORTMEMBER, (D) SAID MOUNTING MEANS COMPRISING A PAIR OF CLAMP MEMBERS, EACHOF SAID CLAMP MEMBERS COMPRISING A FIRST PORTION AND A SECOND PORTIONENGAGING SAID REED MEMBER, (E) SAID FIRST PORTIONS OF SAID CLAMP MEMBERSENGAGING OPPOSTE SIDES OF SAID REED MEMBER AND SAID SECOND PORTIONSBEING LONGITUDINALLY SPACED FROM SAID FIRST PORTIONS AND ENGAGINGOPPOSITE SIDES OF SAID REED MEMBERS, (F) MEANS FIXING SAID FIRSTPORTIONS WITH RESPECT TO SAID REED MEMBER AND MEANS SELECTIVELY OPERABLETO MOVE SAID SECOND PORTIONS LONGITUDINALLY WITH RESPECT TO SAID REEDMEMBER AND SAID FIRST PORTIONS WHEREBY TO VARY THE NATURAL FREQUENCY OFSAID REED MEMBER.